Byzantine Empire

The Byzantine Empire was a Greek Orthodox-Christian empire, the surviving eastern half of the Roman Empire. The Byzantines were named after their capital of Byzantium, renamed Constantinople in honor of Constantine the Great. Byzantine culture was more Greek than Roman, like their origins, and they were also known as the Greek Empire after the collapse of the Western Roman Empire. They reached their peak in the 550s under the reign of Justinian I of Byzantium, who conquered all of North Africa, Italy, and some regions in the Caucasus. He also conquered parts of Spain before his death. The Byzantines declined with the rise of the Seljuk Empire in Asia Minor, and in 1453, almost one-thousand years after their foundation, were conquered by the Ottoman Empire.

Eastern Rome
The Byzantines originated as the "Eastern Roman Empire", which was divided from the Western Roman Empire to facilitate the management of the Roman Empire's regions. The Eastern Roman Empire controlled the Balkans, Asia Minor, the Levant, and North Africa, but in the late 300s and 400s, their lands were conquered by the Sasanian Empire, Vandals, Sarmatians, and Ostrogoths, and by the time of the fall of the Western Roman Empire, the Byzantines were left with the Holy Land, Asia Minor, and only a small part of the Balkans, with the Duchy of Wallachia taking over their Romanian and Bulgarian lands. In 476 AD, with the fall of West Rome, they were left not as the Roman Empire, but a Greek empire with their capital at Constantinople.